Arrangement for transporting disintegrated particulate solids

A pulverized or powdered coal burning arrangement having:

• (a) at least one powdered-coal burner connected to a combustion furnace provided with a fire hearth, where primary air is supplied to said fire hearth through a first connection, having an open end arranged adjacent the powdered-coal burner, and secondary air is supplied to said fire hearth through a second connection,
• (b) a powdered-coal transporting arrangement, including a first conduit, through which powdered coal is fed from a unit continuously to said at least one powdered-coal burner,
• (c) a second conduit for transporting to said unit from a vessel, by pressurized air, said mixture of powdered coal and air having a powdered-coal to air weight ratio higher than the powdered-coal to air weight ratio in said first conduit connected to said at least one powdered-coal burner wherein said unit is effective to transform incoming powdered-coal to air weight ratio into a lower powdered-coal to air weight ratio by supplying to said unit pressurized air through a third conduit so that prepared powdered coal stored in a silo, can be transported to said burner through at least two transporting stages, a first stage where the powdered-coal to air weight ratio in said second conduit shall be greater than twenty and a second stage where the powdered-coal to air weight ratio in said first conduit shall be greater than five, a junction between the first and the second stages arranged in the proximity of the powdered-coal burner and said pressurized air supplied through said third conduit is also used in said burner, and
• (d) the powdered-coal/air mixture for the first stage being supplied to the unit through a conduit extending substantially tangentially in an upper region of the unit;
• and a plurality of conduits, one for said at least one powdered-coal burner extending vertically through the container with exit orifices of said plurality of conduits located adjacent one another in a lower region of the unit.